Abstract/Description

international seminar on Integrating the management of pests, weeds and diseases of cassava in Africa was held in Kampala from 27 June to 1 July 1994
sponsored by CTA and organized by CTA, NRI (Natural Resources Institute, UK) and NARO (the National Agri

Notes

When the rains fail in Africa and harvests are poor there is one crop that can be relied upon as a last resort. In their safe storehouse underground, cassava tubers usually provide an ever ready source of food; but farmers in northern Uganda have found that this year even their last resort has failed. African cassava mosaic disease has destroyed their crop and the disease seems to be spreading south on a broad front across the country at a rate of about 20 km a year. A special task force has been appointed to tackle the problem because the disease must be controlled if further widespread food shortages are to be avoided. Cassava, often referred to as the crop of last resort, is being put at the forefront of the battle for food security.
In the week immediately preceding the announcement of the special task force, an international seminar on Integrating the management of pests, weeds and diseases of cassava in Africa was held just a few kilometres south of the area most affected. The seminar, which was sponsored by CTA and organized by CTA, NRI (Natural Resources Institute, UK) and NARO (the National Agricultural Research Organization of Uganda), was held in Kampala from 27 June to 1 July. Participants came from 23 different countries, 19 of the countries being within Africa's cassava-growing belt. They represented the many different scientific disciplines working in the area of crop protection and were able to highlight the challenges facing cassava producers and researchers alike. It is the first time that an interdisciplinary meeting of this kind on the subject has been covered in Africa.
Cassava, known as the poor man's crop, has not received the same level of funding for research into its development and protection as has been devoted to higher value crops. Furthermore, governments have chosen to rely upon imported grain to satisfy the politically active, urban population. This has done nothing to raise the cash value of cassava which might otherwise have found a good market in town and acted as an incentive to farmers to improve their production. However cassava could be set for a brighter future as governments are forced to accept that imported food is an unnecessary burden on a country's economy if sufficient, locally produced food can be made available. Cassava has advantages over many other crops in that it can be grown on land that is too poor to be used for anything else, a soil condition that is increasing in much of Africa as more marginal land is being put to agriculture and land already in production becomes less fertile. The droughts of recent years have proved the value of cassava to rural and urban populations alike. It is becoming a cash crop of some significance and deserves greater attention from the scientific community. This attention is justified because cassava has the potential to deliver a much higher yield per hectare than it is currently achieving in Africa where the average is 7.7 tons compared to Asia's 13 tons per hectare. One of the most practical and effective ways of increasing yields is to reduce the losses caused by pests, weeds and diseases. The challenge, said John Perfect, Deputy Director of NRI, is to find a means of doing so without promoting a pesticide crisis. Quite apart from financial and environmental considerations, misuse of pesticides can significantly reduce the populations of natural enemies and lead to greater infestations of pests.
Integrating pest management, integrating research
The papers presented at the seminar, and the subsequent discussions, reflected not only the individual interests of the scientists present but also their desire to coordinate their research efforts. This is partly a pragmatic response to financial constraints but it also indicates a recognition that national experiences should be shared and solutions to common problems planned together, a point made by Professor Joseph Mukiibi, Director General of NARO and a member of CTA's Advisory Committee.
The participants set out to identify the most appropriate control measures for each of the major pests and suggest research priorities. For example, it was agreed that there was a stronger case for giving greater priority to research into host plant resistance and cultural control of African cassava mosaic virus than for continuing research into the biological control of cassava mealybug, which has moved from the research into the implementation phase. Dr Peter Neuenschwander, Director of IITA Biological Control Unit, Cotonou, Benin suggested that scientists should be prepared to 'jump over their own shadows' in such cases and put aside their own specific research interests and consider the pest complex as a whole, targeting their efforts in order to bring most benefit to farmers. Participants considered the interaction of different pests and diseases on cassava and the effect on that interaction of various control strategies. They also emphasized the need to undertake further research on the effect of weeds, an area largely neglected in the past but which has considerable potential for reducing yield losses.
The seminar provided a forum for many informal discussions between the scientists present and this should lead to greater understanding of the needs of farmers and effective interaction between scientific institutions in order to meet those needs. In order to further promote this interaction CTA has commissioned a study of all current projects in Africa involving work on cassava. Further details are available from CTA.
The Proceedings of this seminar will be published and their availability will be announced in SPORE.